Space Shuttle
Processing
Space Shuttle Processing
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Orbiter Processing
Initial Access and Safeing
Payload Reconfiguration
Crew Systems
Structures and Mechanisms
Thermal Protection System
Space Shuttle Main Engines
OMS/RCS
Electrical Power System
ECLSS
APU
Communications & Avionics
Orbiter Modifications and Upgrades
Space Shuttle Processing
STS processing is a term used to describe the
preparations and procedures for readying
the Space Shuttle for its next mission
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The STS processing work cycle begins with
the Orbiter’s return to KSC for its coming
flight
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The processing cycle actually starts with the
development of the flight, equipment, and
operations manifest
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Planning begins as early as 5 years before the
planned mission, or in some cases even longer
Space Shuttle Processing
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Primary processing facilities are at KSC
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Supporting facilities include
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Other KSC sites (transportation, logistics, etc.)
JSC
NASA Center – Washington, D.C.
NASA Centers
Primary contractors – worldwide and national
Federal agencies (FAA, NTSB, DoD, etc.)
State agencies
Local contractors
Educational institutions
Media service
Space Shuttle Processing Facilities
Space Shuttle Processing
STS processing consists of four separate elements and five
main facilities
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Orbiter
Orbiter Processing Facility
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SRBs
RSPF and Vehicle Assembly Building
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External Tank
Vehicle Assembly Building
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SSME Engines
SSME Processing facility
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Launch
Launch pad
Space Shuttle Processing
Other KSC facilities involved in STS processing are:
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Hypergolic Maintenance Facility – OMS/RCS maintainance
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Rotation Processing and Surge Facility (RSPF) – SRB storage
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Shuttle Landing Facility
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Operations Support Building – Engineering support
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Logistics Facility
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SRB Retrieval and Disassembly Facility
Space Shuttle Processing
STS launch rates 1988 to 2000
Space Shuttle Processing
Space Shuttle Processing
Space Shuttle Processing
Space Shuttle Processing
Support facilities and functions
The major functions of the Base Operations Contractor
and Installation Operations offices in support of STS
processing include:
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C5 Substation
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High voltage power and emergency power plant for the
Launch Complex 39 area. A 115 kV supply includes 13.8 kV
distribution lines and diesel powered emergency generators
Space Shuttle Processing
Support facilities and functions
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Utility Annex
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Central utility plant provides chilled water, high temperature
hot water, and compressed air for HVAC systems and other
equipment for:
 Launch Control Center
 Orbiter Processing Facilities
 Vehicle Assembly Building
 Operations Support Building
 Thermal Protection System Facility
 Process Control Center
 Logistics Facility
 Component Servicing Facility
Space Shuttle Processing
Support Functions
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Gaseous Nitrogen Plant (off-site vendor production
facility)
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"Propellants North" Fluid Servicing Area and
Compressor/Converter Facility (gases and cryogens)
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Liquid Helium Conversion Facility
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"Propellant South" /CCAS Fuel Storage Area #1
(fuels and chemicals)
Space Shuttle Processing
Support Functions (cont.)
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CCAS Life Support Facilities (Respiratory Protection
Services)
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Non-Destructive Evaluation (NDE) Laboratory
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Sampling and Analysis Laboratory
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Fire & Rescue, Medical, and Security facilities
Space Shuttle Processing
Shuttle Landing Facility (SLF)
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The 15,000 ft x 300 ft concrete runway supports:
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Shuttle landing
Shuttle Training Aircraft (STA) landing approaches
General aviation uses, including:
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Astronaut T-38s
Payload and cargo offload
Military and administrative aircraft operations
Facilities at the SLF include:
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Air traffic control tower
Shuttle and aircraft navigational equipment
Approach and centerline lighting systems
Taxiway and parking ramp
Aircraft fueling and servicing equipment
Space Shuttle Processing
Infrastructure facilities in support of STS processing at KSC
include:
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300 electrical generators, 156 substations, 60 UPS units
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30,000 tons of air conditioning capacity
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40 cranes, 183 hoists, 52 elevators
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500,000 ft of water distribution lines
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Over 170 miles of fiber optic cable
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Over 900 fiber optic transmitters and receivers
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Launch Complex 39 TV system includes 166 cameras, 89 video
recorders, 7770 monitors
Space Shuttle Processing
Management structure of STS Processing
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Space Flight Operations Contract
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Contract managed by NASA JSC
Contractor is United Space Alliance
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Responsible for Orbiter, External Tank (ETE, Solid Rocket
Booster (SRB) and Solid Rocket Motor (SRM)
Responsible for facilities and GSE that supports Shuttle
processing
Subcontract for Space Shuttle Main Engine (SSME)
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Rocketdyne
Space Shuttle Processing
Management structure of STS Processing
(cont.)
Shuttle Processing Director serves as technical
manager for:
 Launch count
 Landing/recovery activity
 Disposition of technical issues for KSC equipment
 Validating that contractor meets NASA processing
requirements
Orbiter Processing
Space Shuttle Processing
Orbiter processing
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After its return from space the Orbiter undergoes
evaluation of its exterior and removal or preparation
for removal of the Orbiter's previous mission
equipment
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Within four hours after reaching KSC the Orbiter is
towed into the Orbiter Processing Facility (OPF) to
begin processing for its next mission
Space Shuttle Processing
Orbiter processing
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Typical processing cycles in the OPF are three
months
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Other major processing activities include Orbiter
Maintenance Down Periods (OMDP) and inspections
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Processing of the Orbiter consists of two major
categories:
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Refurbishment and repair of the Orbiter after its return from
an earlier mission
Vehicle modification, repair, preparation and payload
integration for the following mission
Space Shuttle Processing
Orbiter processing
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Actual processing of the Orbiter in the OPF is
scheduled according to the critical path operation
requirements and the demands on the processing
teams
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These operations have some common scheduling
from flow-to-flow (mission-to-mission)
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Since each mission and vehicle configuration is different,
the scheduled operations often have significant differences
Operations that entail hazardous or toxic materials are
scheduled either first or last to provide maximum safe
working conditions during the processing cycle
Processing operations that are not critical to other work can
be scheduled as needed to improve efficiency and reduce
processing costs
Space Shuttle Processing
Orbiter Processing Facility - KSC
Space Shuttle Processing
Orbiter processing
General processing
operational sequence
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Initial access and safeing
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Runway - Power-down,
venting, pyro disabling,
hazardous gas testing,
etc.
OPF - Continuation of
hazardous material
removal, hypergolic leak
detection, cryogenic
removal, payload transfer
(if needed)
Space Shuttle Processing
Orbiter processing
(cont.)
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Post-flight
troubleshooting
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Inspection and
evaluation of reported
or suspected problems
Systems checkout
Thermal Protection
System (TPS)
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Operations begin with
the inspection of tiles
and batting early in the
processing cycle
because of the length
of time for tile
replacement and repair
Space Shuttle Processing
Orbiter processing
(cont.)
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SSME removal
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Main engines removed
for inspection and
checkout, and to provide
access to the aft
fuselage
Payload bay operations
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Payload removal
Mission kit
reconfiguration
Payload installation (if
horizontal installation)
Space Shuttle Processing
Orbiter processing (cont.)
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Orbiter modifications
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Updates and modifications to the Orbiter and/or its systems
made between missions
Major modifications are performed during the Orbiter Down
Maintenance Period (OMDP), normally once every 7
missions SSME installation
Reinstallation of prechecked SSME engines after necessary
aft fuselage work is completed
Power-on system reverification
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Powered test and checkout of electrical and hydraulic
systems after processing
Space Shuttle Processing
Orbiter processing (cont.)
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Orbiter closeout
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Completion of the processing areas and systems before rollover to
the VAB for assembly on the ET and SRBs
Notes:
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The majority of the processing and integration workforce and time is
allocated to the OPF operations
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Turnaround (from tow-in from the runway to the rollover to the VAB)
varies with scheduling, with the average taking approximately 10
weeks
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Orbiter is then towed (rolled over) into the VAB on a transporter with its
landing gear stowed
Space Shuttle Processing
Orbiter Processing Facility
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Three large rooms (bays)
were constructed in the
OPF building for
simultaneous processing of
three Orbiters
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The fourth processing bay
was placed in a nearby
building
General Orbiter system
checkout, refurbishment,
and/or replacement,
disassembly of the payload
and crew systems is
followed by installation of
the new payload(s) and
crew systems
Space Shuttle Processing
Orbiter
Processing
Facility
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Orbiter processing
continues as the
Orbiter, SRBs and
ET are assembled
in the Vehicle
Assembly Building
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Final processing
and closeout steps
are made on the
launch pad
Orbiter Processing Facility
Initial Access and
Safeing
Space Shuttle Processing
Initial access and safeing
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The Orbiter is prepared for its next assignment as it enters the
processing cycle that begins as the Orbiter comes to a wheel
stop after landing
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The Orbiter contains hazardous materials and explosive devices
that must be removed, stabilized or deactivated before the
vehicle can be accessed by processing personnel
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Crew requires a safe environment while the vehicle is prepared
for their exit
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Initial steps are accomplished by teams of safeing personnel
and equipment deployed after the Orbiter's landing to maintain
critical Orbiter functions, and to reduce or remove hazards while
the crew are readied for exiting the Orbiter
Space Shuttle Processing
Initial access and
safeing
Safeing operations on
STS-57 following a
45-minute cool-down
period
Attachment of Ground
Service Equipment
shown here provides
the Orbiter with
vehicle cooling
Space Shuttle Processing
Initial access and safeing
Preliminary Orbiter safeing tasks include:
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Measure and evaluate the vapors on and near the
Orbiter to ensure safe operational limits for the
safeing teams and crew
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Attach ground service cooling equipment for
personnel and equipment onboard
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Two ground support cooling units are attached to the
Orbiter's right and left T-0 umbilical panel
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RH for mid, aft and forward fuselage equipment
LH for crew compartment and avionics
Space Shuttle Processing
Initial access and safeing
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Install lock pins on landing gear
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Disable active pyrotechnic ordinance by installing
interrupt junction boxes
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Remove any hazardous spent ordinance from Orbiter
Space Shuttle Processing
Initial access and safeing
Final safeing in preparation for towing into the OPF
include:
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Power down of the nonessential Orbiter systems
 The Orbiter continues to be powered by the fuel
cells until ground equipment is switched over in the
OPF primarily to prevent toxic OMS/RCS propellant
leaks
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Payload removal if needed
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Visual inspection of SSME, exterior tiles, structure,
landing gear, etc.
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Tow into the OPF (roll-in)
Payload Reconfiguration
Space Shuttle Processing
Payload reconfiguration
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To be able to accept the new
payloads for each mission,
the Orbiter midbody is
reconfigured with a series of
mechanical adapters and
attachments
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Longeron beams installed
on the sides
Keel beams installed at the
bottom of the midbody
These are the main
structural supports for the
Orbiter payloads and
payload accommodations
Space Shuttle Processing
Payload reconfiguration (cont.)
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Many more specialized
attachments are needed for
each payload that require
extensive fitting and
checkout
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Because of their unique
character, the
reconfiguration procedures
must be well planned and
carefully coordinated to be
completed in the scheduled
processing cycle
Space Shuttle Processing
Payload reconfiguration (cont.)
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Active (motorized for deployable
payloads) or passive (fixed
payloads) latches are attached to
the payload bay structural beams
that are in contact with the payload
trunions
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Another payload attachment beam,
called the sidewall payload carrier
beam, are used for the attachment
of smaller payloads that do not span
across the payload bay
Space Shuttle Processing
Payload reconfiguration (cont.)
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Several other types of
brackets are used to support
the electrical and fluid
interfaces from the vehicle to
the payloads
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Hardware is rearranged for
each flight because each
payload is unique so new
procedure documents called
Test Preparation Sheets
(TPSs) are written and
implemented for each flight
Space Shuttle Processing
Payload reconfiguration (cont.)
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Primary payloads are installed in the OPF using
overhead cranes to lift them from a protective
canister into the Orbiter midbody
 Payload is then secured in place with the
payload retention latches
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The largest payloads are installed and
processed vertically at the launch pad
 Eliminates the loading on the orbiter and
the payload during transportation to the
VAB and to the launch pad
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The larger payload installations are completed
using a Payload Ground Handling Mechanism
(PGHM) inside the Payload Changeout Room
(PCR)
 Located at both of the Launch Complex 39
launch pads (A & B)
Space Shuttle Processing
Crew Systems
Space Shuttle Processing
Crew systems
configuration and
stowage (cont.)
Because each Shuttle
mission and flight crew
is unique, different crew
and safety equipment
installed in the Orbiters
has to be fit checked,
installed and tested for
each flight
Space Shuttle Processing
Crew systems configuration and stowage (cont.)
Among the equipment installed in the crew module that changes for
each flight are:
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Crew seats
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Lockers
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Installation of lockers with experiments, spare components,
personal crew items and food
Safety items
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Installation and testing
Emergency egress devices, checkout and installation
Velcro pads
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Prevents items from floating throughout crew module
Space Shuttle Processing
Crew systems configuration and stowage (cont.)
Specific crew equipment for planned EVA activities must also be installed
and checked. This includes:
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EMU adapter equipment bags
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Stowage of mission equipment bags
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The payload bay also contains crew operated equipment that must be
installed, configured and/or tested for each flight. This category
includes:
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Slidewires
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Tethers
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Safety cables inspected and tested
Safety cables configured and tested
Tools and toolboxes
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Configured
Space Shuttle Processing
Crew systems configuration
and stowage (cont.)
Specific crew equipment for
planned EVA activities
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Foot restraints
 Configured
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Handrails, handholds and
tether points
 Configured
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Instruction and reference
decals
 Inspected
Structures and
Mechanisms
Space Shuttle Processing
Structures and
Mechanisms
The Orbiter structure
and mechanical
systems are
carefully inspected
and evaluated before
each flight to ensure
the safety and
integrity of the
Orbiter, and its crew
and cargo
Space Shuttle Processing
Structures and Mechanisms (cont.)
These inspections cover three general mechanical areas
which include:
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Primary structural assemblies
 Fore, mid, and aft fuselage, wings, tail, body flap, etc.
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Secondary structures
 Attachments, air lock, windows, brackets, fittings, etc.
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Mechanisms - allow movement or access during flight
operation
 Payload bay doors, crew hatches, gear doors, umbilical
doors, etc.
Space Shuttle Processing
Structures and Mechanisms
(cont.)
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Most of the structural inspections
and tests for the Orbiters are done
during their 1-2 year scheduled
Orbiter Maintenance Down Period
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Orbiter upgrades and structural
modifications are completed at the
same time
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The Orbiters have been cycled
through OMDP every eight flights
or every three years
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Wide variation because of the
Challenger and Columbia
accidents
As of 2007, only one OMDP is
planned before the there Orbiters'
scheduled retirement in 2010
Space Shuttle Processing
Structures and Mechanisms (cont.)
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During these upgrades and inspections, the Orbiters are
checked and inspected for corrosion, cracks, stress effects,
and the general condition of the structure in much the same
fashion as an airliner is inspected on a regular schedule
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Discrepancies and problems are evaluated and corrected by
the engineering staff in coordination with the NASA
engineering offices
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Anomalies are corrected in the same fashion, with coordination
of the repairs through the engineering offices
Space Shuttle Processing
Structures and Mechanisms (cont.)
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Each of the Orbiter's window
assemblies are examined carefully for
scratches and pits that could interfere
with the next scheduled mission, or
that would create a hazard if cracking
were to occur
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If a window assembly shows damage
greater than allowed in the engineering
requirements and subsequent analysis,
the respective window assembly is
removed and replaced
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Generally, two or three window sets
are replaced during each flow
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In general, more damage occurs on
longer missions, or in vertical
orientation (gravity gradient) flight, or
during flight into the velocity vector
(forward)
Space Shuttle Processing
Structures and Mechanisms (cont.)
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The payload bay doors are examined for damage due to orbital
debris, thermal stress, and operation. The payload bay radiator
panels are also examined for damage
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Payload attach points are inspected for flight damage in
preparation for installation of new hardware
Space Shuttle Processing
Structures and Mechanisms (cont.)
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The speed brake panels are checked and tested for
structural degradation and washed to remove
corrosion products
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The drag chute compartment is inspected for
damage and refurbished in preparation for
installation of a packaged drag chute
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The aft engine heat shields are removed and
inspected for damage
Space Shuttle Processing
Mechanisms
Orbiter mechanisms checkout consist mainly of testing the
redundancies of the systems that are not normally operated or
checked during flight
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Includes the functional testing per standard procedures (OMI’s)
of individual redundant motors as the criticality of the system
dictates
Systems that are in this category include:
 Payload Bay door drive and latching system
 Radiator deployment and latching system
 Orbiter/External Tank umbilical door drive and latching system
 Orbiter docking system
 Payload retention latches (mission dependent)
 Manipulator positioning mechanism and latching system
Space Shuttle Processing
Mechanisms (cont.)
Mechanisms that require different checkout or servicing include:
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Crew hatches:
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Forces are measured when latching/unlatching and
locking/unlocking the hatches manually
Hatch seal leak checks are performed by pressurizing the area
between the two redundant seals
Landing Gear
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The landing gear extension function is tested and timed
New tires are installed on the main landing gear for each flight
Each of the nose gear tires can be reused once after passing
inspection
Landing gear struts are pressurized for the expected mission
landing weight
Thermal Protection
System
Space Shuttle Processing
Orbiter Thermal Protection
System
Orbiter requires careful
evaluation of the
condition of the entire
Orbiter TPS after each
flight, a process that
begins in the earliest
phase of the Orbiter’s stay
in the OPF
Space Shuttle Processing
Orbiter Thermal Protection System (cont.)
Evaluation
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Evaluation and processing of the TPS includes careful inspection of
the complete outer surface of the Orbiter, beginning with a walkover
inspection of the lower tiles on the runway after landing, cooldown
and safeing
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Engineers examine as much of the Orbiter’s surface as possible to
evaluate debris and orbital damage before it enters the OPF
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A complete insulation inspection takes two weeks or more because of
the large number of surface tiles and the detailed inspections needed
to carefully examine all aspects of the tiles, panels, and blankets
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TPS inspection and evaluation may take even more time if a number of
the tiles and/or panels show only subtle clues of the surface damage
Space Shuttle Processing
Orbiter Thermal Protection System (cont.)
Repair and replacement
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High-temperature Reusable Surface Insulation (HRSI) tile
replacement operations entail exacting measurements and
fitting - generally less than .005" on the edges with a 0.045" ±
.020 gap between tiles
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Since these tiles vary between roughly 1 inch and 6 inches in
depth and can take on complex shapes, each tile is individually
made and fitted by hand which takes approximately two weeks
from removal to completed replacement
Space Shuttle Processing
Orbiter Thermal Protection System (cont.)
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Regions of the Orbiter that require more durable insulation than
the HRSI such as around surface penetrations, gear doors and
the leading edge areas, are covered with Fibrous Refractory
Composite Insulation (FRCI)
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Toughened Unipiece Fibrous Insulation (TUFI) is composed of
about the same silica fiber material in the interior as the HRSI
tiles
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Its more durable surface coating has replaced some of the HRSI
tiles in high-abrasion regions such as below the nose
Replacing 50 to 100 tiles from a typical flight may require from
four or five weeks for a quick turnaround if there are fewer
HRSI tiles to replace, to several months for an extended OPF
stay
Space Shuttle Processing
TPS repair/replacement operations
Space Shuttle Processing
Orbiter Thermal Protection System (cont.)
RCC panels
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The highest temperature insulation on the Orbiter is the
Reinforced Carbon Carbon (RCC) panels that protect the
leading edges of the wings and the nose cap
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Careful inspection of the leading wing edge panels may require
removal and replacement, and includes the inner and mounting
surfaces
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Modifications to the RCC panels because of the Columbia
accident included improved inspection techniques, protective
barriers for the wing front strut
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Because of the time needed for processing, careful
examination and evaluation of each of the RCC panels takes
place soon after the Orbiter arrives for processing to facilitate
repairs and/or replacement
Space Shuttle Processing
Orbiter Thermal Protection System (cont.)
Flexible insulation
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In addition to the replacement of HRSI, LRSI, FRCI and TUFI tiles,
the Orbiter's other thermal protection coverings that include Felt
Reusable Surface Insulation (FRSI) pads, and Flexible Insulation
Blankets (FIBs) must be repaired, and if necessary, replaced
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Since the flexible blankets are much larger and are more easily removed
and replaced than the tiles, the process of repair/replacement is
generally much shorter
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Thermal barriers for the external joints (gear & umbilical doors, etc.)
and gap seals must also be checked, repaired, and modified as
necessary
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Thermal barriers and gap fillers are also inspected for compliance
with often increasingly rigorous specifications
Space Shuttle Processing
Orbiter Thermal Protection System (cont.)
VAB processing
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Nearly all of the TPS repair, replacement and modification is
done in the OPF
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An exception is the final nose gear door step and gap
evaluation that takes place after the Orbiter is mated with the ET
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Loads on the Orbiter structure can result in misalignment of the
tiles, seals, and thermal barriers which must be corrected to
ensure an accurate fit for a positive thermal seal
Space Shuttle Processing
Orbiter Thermal Protection System (cont.)
Pad processing
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SSME work during launch pad preparation requires access to
the aft compartment by engineers and technicians

When completed, the base heat shield carrier panels are
replaced as part of the closeout process

These panels protect the engine and components in the aft
compartment from the high-temperature exhaust during
launch

Any damage to the TPS from the integration process or
transportation to the pad is repaired before launch
Space Shuttle Processing
Source breakdown of events requiring TPS processing
Space Shuttle Main
Engines
Space Shuttle Processing
SSME/Main Propulsion System

Space Shuttle Main Engines are high performance
engines which require careful inspections and
checkout during Space Shuttle processing and
integration
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These inspections and tests are performed before,
during, and after the Orbiter’s stay in the OPF
The arriving Orbiter has all three SSMEs removed and
transported to the SSME Processing Facility (SSMEPF)
for inspection and refurbishment, with some components
repaired or replaced, or at times, upgraded
A different engine set that has undergone inspection,
refurbishment and testing is then installed in the Orbiter
while in the OPF
Space Shuttle Processing
SSME/Main Propulsion System (cont.)

Processing, testing, and inspection of the SSMEs
begins on the runway after the Orbiter lands with a
walkdown visual inspection
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The engines are checked for any visible damage and the
external aft section is checked for any loose hardware
At this time, throat plugs are installed, and purge lines and
access ports are plugged, to protect engines from
contamination
Space Shuttle Processing
SSME - OPF processing
Once the Orbiter is towed into the Orbiter Processing Facility,
the engines are readied for removal and transportation to the
SSME engine shop at the Kennedy Space Center
Initial processing includes:
 High Pressure Turbine Pump bearing drying with heated GN2
(within 48 hr of landing)
 Visual inspection of interior and exterior
 Low pressure turbopump turbine torque check
 Hydraulic activation of actuators to move engines into
correct alignment for removal
 Aft heat shield removal
 Engine heat shield removal
 SSME removal
Space Shuttle Processing
SSME processing
After the engine testing is
completed in the
SSMEPF, the SSMEs are
prepared for installation
in an Orbiter
Checkout continues with
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Interface leak checks
Gimbal nozzle
clearance – hydraulic
actuator check
Walkdown inspection
Nozzle cover
installation
Aft heat shield
installation
Space Shuttle Processing
SSME processing - VAB
While the Orbiter is processed in the VAB, the
engines and main propulsion system are checked
These steps include:
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Orbiter/ET interface leak test
SSME leak test with GN2
Nozzle cover removal
Trickle purge activation (purges humid/contaminated air
from engines)
Space Shuttle Processing
SSME processing – Launch Pad
As the Orbiter is processed for launch on the pad, the SSME/MPS is checked in
preparation for operation
These preparations include:

Flight Readiness Testing (FRT)

Helium signature test – uses aft compartment for a systems leak test similar to
encapsulation leak test

Electrical system checkout

Ball seal leak check (5 ball valves and seals on each engine)

Walkdown inspection

Helium bag leak check

Main combustion chamber polishing

Nozzle cover removal

Purging

Engine heat shield installation
In preparation for the propellant loading and firing and engine ignition software
loads, sensor and igniter checkouts and inert purges are performed
OMS/RCS
Space Shuttle Processing
OMS/RCS Processing
OMS and RCS system, propellants, and components
are hazardous, requiring careful processing and
preparation steps during servicing and checkout

Preparations may include removal of the OMS
pods and Forward Reaction Control Section
(FRCS) if internal work is required


If removal is necessary, those OMS/RCS sections are
taken to the Hypergolic Maintenance Facility (HMF) for
servicing
HMF facility is separate from all other processing
buildings for safety considerations
Space Shuttle Processing
OMS/RCS Processing (cont.)

Several procedures require evacuation of the OPF
and the use of hazardous materials suits (Self
Contained Atmospheric Protective Ensemble or
SCAPE)

Required for workers that might be exposed to the
fuel (monomethyl hydrazine or MMH) or oxidizer
(nitrogen tetroxide or NTO) from the OMS/RCS
plumbing and/or components
Space Shuttle Processing
OMS/RCS Processing (cont.)
Preliminary preparation of the OMS/RCS system
begins as the Orbiter is powered down after
landing, with the safeing crews first to reach the
Orbiter

Deservicing of the Orbiter is begun almost
immediately in order to reduce or remove the
hazardous components and toxic gas exposure to
the flight crews and ground processing crews

OMS/RCS systems leak detection is initiated and
nozzle plugs installed
Space Shuttle Processing
OMS/RCS Processing (cont.)

Gaseous nitrogen used to pressurize the OMS
valves is vented with selectors located in the
cockpit

Teams deactivate and safe pyrotechnic
components, and service the purge, vent and drain
(PVD) system lines

After the Orbiter has been towed into the OPF, the
hazardous fuels, including MMH, NTO and
ammonia, are again checked for leakage from the
system lines, storage tanks, and interface
Space Shuttle Processing
OMS/RCS Processing (cont.)

Fuel and oxidizer tanks are not drained since the
propellants are stable

Other fluids including the reactants for the fuel
cells (liquid and gaseous hydrogen and oxygen)
are removed and purged from the PRSD tanks and
lines soon after the Orbiter arrives in the OPF
Space Shuttle Processing
OMS/RCS OPF processing
While the Orbiter is in the OPF, checkout and functional tests
are performed on the forward RCS and aft OMS pods which
include:








FRCS interface verification
LH and RH pod interface verification
RCS UTPA inspection and replacement
FRCS functional checkout
LH and RH pod functional checkout
Oxidizer and fuel crossfeed checkout
Fore and aft RCS valve, regulator, and distribution checkout
LH and RH pod screen tests for fuel and oxidizer
Space Shuttle Processing
OMS/RCS – launch pad processing
Soon after the assembled STS arrives at the launch pad, the
OMS/RCS system undergoes propellant servicing that
includes fuel and oxidizer tank fill and checkout
 Hypergolic servicing


Nitrogen pressurization system servicing


Normally scheduled within a week after arrival since the
hypergolics are stable
Normally scheduled one week or less before launch to reduce
leakage losses
Helium pressurization system servicing

Normally scheduled one week or less before launch to reduce
leakage losses
Space Shuttle Processing
OMS/RCS processing
Thrusters

OMS thrusters are not generally removed for inspection,
testing, or checkout unless a problem occurs in flight or an
inspection dictates removal



To improve reliability the engines are removed and replaced
with new or rebuilt units every other OMDP
Testing is done when necessary in a vacuum chamber
RCS thrusters are not generally replaced unless problems
occur, which are most commonly leaks

Since the thrusters are sensitive to temperature and pressure
changes, a block of thrusters is replaced if one on a manifold
indicates a problem
Electrical Power System
Space Shuttle Processing
Electrical Power System
After the Orbiter has landed and has been towed into
the OPF, the GSE equipment is connected to
supply the necessary power for operation of the
Orbiter functions through the rear T-0 panels

Between the landing and the GSE power
connection, the three cells provide power for the
Orbiter systems


PRSD must have sufficient reactant reserve for critical
operations, especially the OMS/RCS valve closure
Fuel cells must also be drained of water and cooled
during that period to prevent internal damage
Space Shuttle Processing
Electrical Power System (cont.)

During the initial safeing of the Orbiter
after its return from space, the pyrotechnic
assemblies are disconnected and some
removed

This is generally accomplished with Load
Control Assemblies (LCA) being installed to
interrupt critical firing paths to the ordinance
Space Shuttle Processing
Electrical Power System processing - OPF
During the Orbiter processing cycle in the OMS, the Electrical
Power System is tested and checked during a number of
operations. The major checkout operations include:

Orbiter power-up:



Electrical power distribution for tests and checks for other
systems and components
These tests include nearly all functions which requires nearly
continuous power for the processing cycle
Shuttle Connector Analysis Network (SCAN) tests:

The myriad of connectors throughout the Shuttle must be tested
and checked for proper operation during the many stages of
processing and assembly
Space Shuttle Processing
Electrical Power System processing - OPF

Orbiter lighting validation:


RMS test and checkout:


Checkout and testing of the Remote Manipulator System
functions
Wiring modifications:


Checkout of the Orbiter lighting system throughout the crew cabin
and the payload bay
Critical testing of any modifications for the Orbiter ant its payload.
Since each payload is different, these tests are conducted for
each mission
Ordinance wiring replacement and resistance testing:

Testing and checkout of the critical wiring for the ordinance
circuits
Space Shuttle Processing
Electrical Power System processing – OPF (cont.)

Orbiter EPS modifications and payload-specific
modifications

Wiring repairs and troubleshooting

Line Replaceable Unit (LRU) and panel installations

EMU Orbiter interface test:

Test and checkout of the Extravehicular Mobility Unit power
and wiring interface with the Orbiter
Space Shuttle Processing
Electrical Power System processing – OPF (cont.)

SSME aft connector inspection:

Main engine wiring and connector testing

Ku-band radar and communications system
turnaround test

Payload and payload bay verification test and
checkout
Space Shuttle Processing
Electrical Power System processing – OPF (cont.)

Instrumentation system verification

Master Events Controller (MEC)
verification:


Pyro controller checkout
Pyrotechnic Initiator Controller (PIC)
verification
Space Shuttle Processing
Electrical Power System processing - VAB
While in the VAB, the EPS checkout and testing
includes the hazardous gas detection circuitry and
preliminary pyrotechnic installation checks and
testing

ET/Orbiter electrical monoball assembly and testing:


Monoball is the electrical interface panel for electrical
cabling connectors between Orbiter & ET attached to the
right and left umbilical panels
Orbiter/ET interface test:


Test and checkout of the electronic and power circuitry
between the External Tank and the Orbiter
Space Shuttle Processing
Electrical Power System processing – VAB (cont.)

SRB cabling and function tests:


Check and test of SRB function wiring through
the ET/Orbiter interface
Installation of pyro charges:


Ordinance/pyrotechnic charges are placed in
position as late in the flow as possible to
reduce the potential hazards during processing
and integration
Space Shuttle Processing
Electrical Power System processing – Launch Pad
While the Shuttle is on the launch pad, a number of
electrical tests and checkouts are performed to
ensure that the electrical systems and
connections are operational. These include:

SRB/ET/Orbiter/Pad interface test:


Test and checkout of the Shuttle systems and pad
support interface
Pyro charges and wiring completed:

Ordinance circuitry completed
Space Shuttle Processing
Electrical Power System processing – Launch Pad (cont.)

Ordinance (pyro) resistance & load testing:


Range Safety System (RSS) functional test:


Ordinance wiring test and checkout under low current
load
Test and checkout of the range safety system on the
Shuttle vehicle
Final Pyro Initiator Controller test
Space Shuttle Processing
Electrical Power System processing – Launch
Pad (cont.)

Master Events Controller final checkout

Launch pad electrical validation and test

Hazardous gas detection system test and checkout:


Test and checkout for the hydrogen, nitrogen and oxygen
detection system for crews working on the last processing
steps before launch
MPS helium signature leak test:

Leak check for SSMEs using pressurized helium in the
engine interior and a mass spectrometer to detect helium in
the aft compartment
Space Shuttle Processing
Fuel Cells
The Orbiter fuels cells that provide electrical power for the entire
vehicle require approximately 250 man-hours of processing
vehicle flow to ensure operational reliability for all aspects of
the Orbiter’s flight
OPF processing

Fuel cell load removed, then powered-down

Cryogenic LH2 and LOX drained from PRSD system
Space Shuttle Processing
Fuel Cells – OPF (cont.)

Helium inert purge of PRSD and fuel cell
systems to support safe entry into
payload bay

Fuel cell in-depth diagnostics to evaluate
system degradation

Fuel cell changeout if required
Space Shuttle Processing
Fuel Cells – OPF (cont.)

PRSD O2/H2 tank removal/installation as required
to support next flight

PRSD and fuel cell system pressure decay test

Overboard leak checks

Maintain helium pressure in the tanks to provide
constant internal pad pressure to the fuel cells as
well as prevent moisture induced corrosion within
the tanks
Space Shuttle Processing
Fuel Cells
VAB processing

System monitoring only (if required for long term
storage)
Space Shuttle Processing
Fuel Cells
Launch pad processing
 LOX and LH2 servicing of PRSD tanks (loaded
from mobile tanker approximately two days
before launch)

Fuel cell activation (approximately 15 hr before
launch)

High load fuel cell test
Space Shuttle Processing
Fuel Cells - Launch pad (cont.)

System integrity (cold exposure) test

O2 and H2 leak check with GN2 background in
Payload Bay/midbody

Payload Bay/midbody GN2 purge test for GOX
and GH2 leaks

Full Orbiter power switchover to fuel cells
(approximately 2-3 minutes before launch)
ECLSS
Space Shuttle Processing
Environmental Control & Life Support System
Prior to landing and until shortly after wheel stop, thermal control
is provided by the volume of Freon-21 in the radiators which
was "cold-soaked" during the last few hours of de-orbit
preparations using the Flash Evaporator System
Processing begins after wheel stop

The active cooling system that provides thermal conditioning
for the crew and equipment is switched to the ammonia boiler
system until the ground support system is manually
connected to the Orbiter left side T-0 Interface Panel

Within 2 ½ hours of wheel stop, the vacuum vent duct is
purged with nitrogen to dilute the concentration of hydrogen
gas that is captured from the fuel cell water
Space Shuttle Processing
ECLSS
Initial OPF processing

Waste Control System (WCS), which is essentially the
commode and waste storage, is removed and returned to
JSC for cleaning and refurbishment

The waste water system is flushed to remove salt
precipitates and to reduce bacterial growth

Flash Evaporator System inspection and purge to reduce
corrosion

Purge and evacuate the ammonia boiler vent line to
remove moisture
Space Shuttle Processing
ECLSS
General OPF servicing

Plug ammonia system, vacuum vent, and flash
evaporator ports to avoid debris and
contamination

Cabin and avionics fan and filter cleaning

Humidity separator testing and flush
Space Shuttle Processing
ECLSS
Final OPF servicing

Ammonia servicing and purge

GN2 servicing

Potable water drain and servicing
Space Shuttle Processing
ECLSS
VAB processing

Processing of the ECLSS in the VAB after
integration consists of power-up testing
and ground cooling loop testing with the
Ground Support Equipment
Space Shuttle Processing
ECLSS - Pad processing

ECLSS processing on the pad includes an additional Flash
Evaporator purge because of its critical function while on
orbit and the nature of the harsh coastal environment

Gaseous oxygen for the crew compartment is provided by
heated cryogenic oxygen from the onboard LOX storage and
distribution system which is loaded during PRSD tanking on
the pad about two days before launch

Vacuum vent line purge with nitrogen prior to fuel cell start
and at each 24 hour interval (in the case of launch scrubs
while keeping the fuel cells on-line)
Space Shuttle Processing
ECLSS - Pad processing (cont.)

Removal of plugs from Ammonia Boiler vent,
Vacuum Vent and Flash Evaporator vent ports

Perform a final 2 psid crew module pressure leak
check after final crew hatch closure to ensure
cabin pressurization integrity
Space Shuttle Processing
ECLSS
Mission variations

Missions beyond 16 days duration called extended duration
operations employ additional PRSD LH2, LOX and GN2 tanks

Provides additional electrical power, atmospheric gas, and
breathing oxygen

Extended Duration Operation (EDO) package also includes a
Regenerative CO2 Removal System (RCRS) which is a dual
amine absorption bed that replace of the heavier LiOH system
and canisters

Two LiOH canisters are still carried on the extended duration
missions for backup
APU
Space Shuttle Processing
APU/Hydraulic System
Orbiter APU processing tasks
Servicing and checkout of the APU/hydraulic systems during
processing covers the mechanical system and components, and
the fuel system. Those tasks include:

Deservicing hydrazine fuel tanks after Orbiter arrival in the OPF

Replacing APU lubricating oil

Servicing APU water coolant system

Hydraulic system fill, bleed, and checkout

Water Spray Boiler (WSB) checkout and servicing

Orbiter GN2 accumulator servicing
Space Shuttle Processing
APU/Hydraulic System
Pad processing
Before launch, the APU/hydraulic system requires:

Servicing GN2 pressurization tanks

Servicing hydrazine fuel tanks (Orbiter and SRB)

APU confidence run (hot fire)

APU leak and functional test

Hydraulic system functional testing

In addition, the APU system requires leak and electrical testing
during the processing cycle and before launch
Communications &
Avionics
Space Shuttle Processing
Orbiter Communications
Orbiter communications system undergoes little rework in the
processing cycle in spite of the different mission
requirements

The UHF, S-band, and Ku-band communications are standard
to all Orbiters and flights, and provide the necessary links
from the Orbiter to ground, and for Orbiter
intercommunications

Because most interfaces to the Orbiter communications
systems are standardized, and the communication format is
exactly specified for the payloads, the checkout procedures
for Orbiter communications during processing is done
primarily during payload checkout
Space Shuttle Processing
Orbiter Communications
OPF Processing

Checkout and testing of the Orbiter communications system
takes place either in the OPF or on the launch pad

Processing and checkout of the Ku-band communications
consists primarily of a powered checkout of the system and
radar antenna while the Payload Bay doors are open and the
antenna is deployed

Further testing of UHF and S-band systems is done on the
launch pad

Since the Ku-band antenna is stowed in the Orbiter Payload
Bay, it cannot be activated until the Orbiter is on orbit and the
payload bay doors are opened

Hence Ku-band processing and testing is limited to the Orbiter
Processing Facility.
Space Shuttle Processing
Orbiter Communications
Pad Processing

Communications system checkout resumes on the
launch pad when the T-0 umbilical line S-band
communications are checked, then again when the
communications are checked during the Terminal
Countdown Demonstration Test (TCDT)

A number of automated communications tests are
performed during the countdown cycle to ensure all
systems associated with the ground and Orbiter
communications are functioning
Space Shuttle Processing
Avionics and Flight Control Systems
Reliability in the flight control system is provided by a
combination of the software architecture and redundant
hardware

Comprehensive testing of each of the Shuttle’s digital
avionics systems is completed prior to each mission to
ensure safe operation

Hardware and software testing procedures are done in the
processing (OPF), integration (VAB) and prelaunch (launch
pad) stages of the vehicle's preparation for flight

Testing procedures are often accomplished by utilizing the
numerous digital processing systems used for following
Space Shuttle processing and integration, such as the Launch
Processing System (LPS)
Space Shuttle Processing
Avionics and Flight Control Systems
Software

The Shuttle’s digital system software is divided into two
principal areas; flight software and ground software

Majority of the ground software is written in a special
language known as Ground Operations Aerospace Language
(GOAL)


GOAL, which was developed at the Kennedy Space Center in the
1970’s, allows for extremely fast command and control of the
Orbiter systems
An effort was made at KSC to replace the LPS GOAL software
and hardware with C++ software and modernized computer
hardware known as the Checkout, Launch, and Control System
(CLCS)
Space Shuttle Processing
Avionics and Flight Control Systems
Software

Ground testing software is managed by the
processing teams at Kennedy Space Center, while
the flight software is managed by the Johnson
Space Center

Coordination between the NASA personnel and
contractor teams is a continuous operation
because of the complexity of the systems and the
extreme reliability required for safe manned space
vehicle flight
Space Shuttle Processing
Avionics and Flight Control Systems
Processing and testing categories
The various tests and evaluation operations for the avionics,
digital, and flight systems are classified into several
categories







Turnaround testing
System troubleshooting
Data analysis (trend development and identification, etc.)
Launch execution
Metric data collection
Design reviews for upgrades and new technologies
Ground software review
Space Shuttle Processing
Avionics and Flight Control Systems
Primary digital and avionics groups
The primary digital and avionics groups represent the major divisions
in the systems and components, but not necessarily the separate
testing or operational check areas
Many of the subsystems and systems overlap in many of their
functions; an example being the Data Processing System (DPS)
control over most of the Space Shuttle system functions
The primary groups are:





Data Processing Systems (DPS)
Flight software (FSW)
Electrical Flight Control Systems (EFC)
Guidance and Navigation Systems (G&N)
Space Shuttle Main Engine Avionics (SSMEA)
Space Shuttle Processing
Avionics and Flight Control Systems
Primary processing & integration tasks

The critical checks on the Shuttle digital and
avionics systems take place at specified intervals

The most critical tasks for each system take place in
the OPF, VAB and PAD processing facilities at KSC
Space Shuttle Processing
Avionics and Flight Control Systems
Primary processing & integration tasks

Final power up and checkout of many Space Shuttle systems
occurs at the launch pad during launch countdown
The following list is representative of some of the critical tests
required on each of the STS vehicles during processing

Data Processing System (DPS)
 DPS Computer Complex Checkout
 Dedicated display/HUD checkout
 Multifunction CRT Display System (MCDS) checkout
 Flight Software Load Dump and Compare
Space Shuttle Processing
Avionics and Flight Control Systems

Electrical Flight Control System (EFC)






Aero/Ascent Thrust Vector Control (ATVC)
checkout
Space Shuttle interface test (Orbiter, SRB, ET)
Power Redundancy Testing
Manned Maneuvering Unit (MMU) operations
Nose Wheel Steering (NWS) checkout
Brake/Antiskid system checkout
Space Shuttle Processing
Avionics and Flight Control Systems

Guidance & Navigation System (G&N)




Inertial Measuring Unit (IMU) functional checkout
Star Tracker inspection and self test
Air Data Transducer Assembly (ADTA) checkout
SSME Control


Pad Flight Readiness Test (FRT)
SSME engine avionics checkout (sensors, pneumatics,
igniter, actuator, power supply, command controller, skin
temp, flight readiness, controller load)
Space Shuttle Processing
Avionics and Flight Control Systems
Additional tests are made on the Space Shuttle’s
digital, flight and avionics systems based on
conditions or events that might require retesting
(contingency due to hardware failure), or upon
return from modification and upgrades from the
OMDP

Approximately fifty percent of the testing done at
KSC is unplanned and is due to system anomalies
Space Shuttle Processing
Avionics and Flight Control Systems

Examples of tests run for contingency events are:





Flight control aerosurface checkout
Flight control frequency and step response
OMS/RCS checkout in the Hypergolic Maintenance
Facility
DPS/EFC/FSW/G&N/SSMEC retesting for Orbiter lightning
strike
Examples of testing after OMDP return include:

HUD checkout
Star tracker installation and checkout

NWS interval testing

Space Shuttle Processing
Processing emphasis

Processing and checkout by each of the various
Space Shuttle teams requires vastly different
procedures and emphasis because of the widely
varied system functions

The digital, flight control, and avionics teams
handle extensive testing routines. EFC engineers
are also involved in all hydraulic operations

DPS engineers are also involved in the tests of
most of the other systems since most functions
are under GPC control
Space Shuttle Processing
Processing emphasis

To enhance safety, reduce errors, and optimize the
man-hours for each flow, the emphasis of the
digital and avionics teams is on measuring,
improving testing and launch execution efforts

This continual improvement is accomplished by
examining the underlying principles and
philosophies of the vehicle testing and its
effectiveness

Emphasis is also placed on the lessons learned
from previous STS missions, and from testing and
evaluation experience
Orbiter Modifications
and Upgrades
Space Shuttle Processing
Orbiter Modifications
Each Orbiter undergoes repairs, upgrades, improvements,
payload kit installations, and other modifications during their
processing and integration cycles

These modifications can be for payload installations, or to
increase performance, or to improve operating costs, repair
worn or damaged equipment or materials, or to correct
potential or existing problems

The entire collection of changes to the Orbiter, and the ET
and SRBs, could be simply called modifications, since the
same principle of work authorization, work completion, and
documentation is used to accomplish each
Space Shuttle Processing
Orbiter Modifications

Separate projects and programs direct
these changes through different channels
to be completed during the processing and
integration flow


Modifications to the Orbiter, ET, and SRBs have
different origins but are completed by the same
processing teams
The most extensive of these modifications
is performed during the Orbiter
Maintenance Down Period
Space Shuttle Processing
OMDP

OMDPs were completed previously at the Rockwell
Palmdale, California plant

OMDP inspections and modifications now take
place in the Kennedy Space Center within the OPF

OMDP maintenance and upgrade program is
scheduled every seven to eight flights for each
Orbiter, or approximately once every three years
Space Shuttle Processing
OMDP

OMDP provides the most efficient means of
comprehensive inspection and major
modification for the Orbiter because of the
ample time available, and because of the
scheduling conflicts that can arise during
the normal vehicle flow

OMDP period is approximately 14 months in
length, with some variation due to arrival,
departure and scheduling differences
Space Shuttle Processing
Upgrades
Orbiter modification approval is generally a different
procedure from the upgrade approvals, even
though both may include large-scale or small-scale
alterations and come from the same engineering
office at JSC, and may even be done at the same
time or at the same site

Generally, upgrades cover longer-term planning
and approval, and may include larger-scale
alterations than most modifications

The Shuttle upgrade program is an ongoing
improvement program for extending the operational
capability and safety of the Shuttle that was
to extend through the year 2012
Space Shuttle Processing
Upgrades

The overall program has been altered to bring the
Orbiters to a fleet standard before the retirement of
the Orbiters, currently scheduled for 2010, or at the
completion of the International Space Station

Priorities for NASA's STS upgrade program
include:





Safety
Supportability
Reliability
Maintainability
Cost reduction
Space Shuttle Processing
Upgrades
NASA's emphasis on STS improvements and
upgrades in the post-Columbia era are focused on
the safety and reliability of the flight and ground
operations
Many of the more visible upgrade projects are on the
External Tank and the attachment to the Orbiter in
compliance with the Columbia Accident
Investigation Board recommendations. Some of
those improvements/upgrades are:

Bipod attachments between the ET and Orbiter
have had foam replaced with electric heaters
because of the susceptibility of the insulation foam
on the ET to shed during ascent
Space Shuttle Processing
Upgrades

Improved foam application procedures to reduce
the incidence of foam shedding from the ET

Removal of the Portrubance Air Load Ramp foam to
reduce the incidence of foam shedding from the ET

Improvements in the thermal insulation for the LOX
bellows on the ET

Addition of leading-edge temperature sensors on
the Orbiters wings to measure thermal distribution
Space Shuttle Processing
Upgrades – post-Columbia

Addition of sensitive accelerometers to the
Orbiter wing's leading edges to help identify
possible damage during ascent or descent

Improved bolt catchers on the pyrotechnic
devices used to separate the SRBs from the
ET

Improved booster separation motors to
reduce potential damage to the Orbiter
Space Shuttle Processing
Upgrades – post-Columbia

Addition of inspection cameras to the forward
section of the SRBs to view the Orbiter and ET
during ascent

Addition of an inspection boom to the Orbiter's
Remote Manipulator System to provide detailed
inspection of the Orbiter after arrival on orbit, and
again to check for possible micrometeoroid damage
before deorbit

Development of tools, materials, and procedures for
repairing damage to thermal tiles and RCC panels
on orbit
Fish-eye view of
the Orbiter's new
Multifunction
Electronic Display
Subsystem
(MEDS) glass
cockpit shown
here in the
Johnson Space
Center's Shuttle
Mission Simulator
The End